Physics 2010 JAMB Past Questions - Question 44: In Faraday's law of electrolysis, a graph of mass deposited against the quality of electricity is plotted . The slope of the graph gives

Correct Answer

A

Explanation

Faraday's law of electrolysis relates the mass of a substance deposited during electrolysis to the quantity of electricity passed through the electrolyte. The relationship is given by the equation:

\(m = \frac{Q * M}{z * F}\)

Where:
- \(m\) is the mass of the substance deposited,
- \(Q\) is the quantity of electricity (in Coulombs) passed through the electrolyte,
- \(M\) is the molar mass of the substance being deposited,
- \(z\) is the number of moles of electrons transferred per mole of substance (the charge number or valency), and
- \(F\) is the Faraday constant (approximately 96,485 C/mol, which is the charge of one mole of electrons).

If you were to plot a graph of mass deposited (\(m\)) against the quantity of electricity (\(Q\)), the slope of the graph would be equal to \(\frac{M}{z * F}\).

So, the slope of the graph gives you the ratio of the molar mass of the substance being deposited (\(M\)) to the charge number (\(z\)) of the ions involved in the electrolysis, divided by the Faraday constant (\(F\)). This ratio is a constant value for a specific substance under particular conditions.